Field of the Invention
The present invention relates to a substrate processing apparatus for processing a substrate such as a semiconductor wafer and to a method for processing the same.
Description of Background Art
A substrate processing apparatus for processing a semiconductor wafer (hereinafter referred to as a “wafer”) such as plasma etching may include the following: between a load port provided with a front opening unified pod (FOUP), which is a container to accommodate multiple wafers, and a process module (vacuum processing chamber) for performing plasma treatment on wafers; a loader module which is kept under atmospheric ambience and is for loading/unloading semiconductor wafers to/from a FOUP; a transfer module which is kept under vacuum ambience and is for loading/unloading wafers to/from the process module; and a load-lock module which is positioned between the loader module and the transfer module and is kept switchable between atmospheric ambience and vacuum ambience.
In such a substrate processing apparatus, a first transfer device is provided in the transfer module and a second transfer device is provided in the loader module, and those devices transfer wafers between the load port and the process module. Here, the first transfer device is driven mainly by a motor, for example, and opening/closing the gate valve for communication/isolation between the process module and the transfer module is controlled by an air cylinder (see JP 2010-074073A). The entire contents of this publication are incorporated herein by reference.
FIG. 4 is a view schematically showing the structure of a wafer transfer control system of the aforementioned substrate processing apparatus. To simplify the description, first transfer device 94 is set to be driven by motors (94a, 94b). The total control on the substrate processing apparatus is performed by master controller 90. As a lower controller of master controller 90, robot controller 91 is provided to control motors (94a, 94b) of first transfer device 94. Opening/closing gate valve 95 for communication/isolation between the process module and the transfer module by gate-valve driver 92 is controlled by master controller 90. In addition, master controller 90 also controls elevator-pin motor 93 to lift/lower elevator pin 96 which is provided in the process module and handles the delivery of a wafer to/from the first transfer device 94.